Customers who bought a box license receive two serial numbers - one for the workstation and one for the render nodes. To install the box version, download the unified installer and install Corona. Then run 3ds Max, set renderer to Corona, and hit Render. When a licensing window pops up, select "Activate Box license". The license usually activates automatically after typing in the serial number. If not, you will need to copy the request key shown by Corona, paste it here together with the serial number, and copy the activation code back to Corona. See this article for more info, troubleshooting, and activating multiple computers at once.